You can know many things non-inferentially

For which you run into Agrippa's Trilemma, because now you have to make a reasoned argument as how you know that. Or you simply declare dogmatically that it is so. hit infinite regress or beg the question.
What you said was this: "I know, that you can know many things non-inferentially."
For which I answer: "How do you know that?"
And off we go into Agrippa's Trilemma. :)

The hidden assumption you hold can be viewed like this:
# We can explain knowledge with reason, logic and experience.
Versus these 2:
# Knowledge is meaningless, unless we can explain knowledge with reason, logic and experience.
# The idea, that we can explain knowledge with reason, logic and experience, is just that - an idea, which doesn't hold up to reason and logic. In other words reason and logic are limited and can't explain knowledge including if we can fundamentally trust our experiences.

What you said was this: "I know, that you can know many things non-inferentially."
For which I answer: "How do you know that?" — Mikkel

My point is that your argument doesn't prove that we don't know things non-inferentially, and since most people believe that they do know things on the basis of their sense experience (and not arguments), your argument simply doesn't engage the most plausible view out there regarding knowledge. I'm not trying to assert that I'm right that we do know things non-inferentially, I'm just saying that your argument doesn't show that we don't (and so I don't have to prove that we do, in order to show that your argument doesn't succeed).

My point is that your argument doesn't prove that we don't know things non-inferentially, and since most people believe that they do know things on the basis of their sense experience (and not arguments), your argument simply doesn't engage the most plausible view out there regarding knowledge. I'm not trying to assert that I'm right that we do know things non-inferentially, I'm just saying that your argument doesn't show that we don't (and so I don't have to prove that we do, in order to show that your argument doesn't succeed). — Fafner

I don't know ;) how to get this across. It is pointless to point out that my argument about knowledge fails, if all arguments about knowledge fail.
In short:
Me: Argument X.
You: It fails.
Me: Argument Y.
You: It fails.
Me: Argument Z.
You: It fails.
...
If all arguments about knowledge fails, then why single out the skeptical ones?
What is the point, Fafner?
That you believe you have knowledge, means you have knowledge? Is that your point?
It doesn't hold up! I believe that you don't exist, means that you don't exist? Or rather do you believe that all beliefs work?

Further you claimed that there are things, which are know non-inferentially, so would you please explain, how you know that?

I don't know ;) how to get this across. It is pointless to point out that my argument about knowledge fails, if all arguments about knowledge fail. — Mikkel

I don't understand what you mean. If your argument fails, then it fails, which means that you haven't proved your conclusion (skepticism or whatever it was). So it's not pointless.

That you believe you have knowledge, means you have knowledge? Is that your point? — Mikkel

No, my point is that your reasons for denying that we have knowledge aren't very good (and I'm not trying to prove to you that I do have knowledge - I've got better things to do).

Further you claimed that there are things, which are know non-inferentially, so would you please explain, how you know that? — Mikkel

I already told you - by perceiving them. This is what 'non-inferential' means - the reason for your belief is not in the form of an argument which you can give to someone, it just suffices to have the right sort of experience without needing any additional reasons.

I already told you - by perceiving them. This is what 'non-inferential' means - the reason for your belief is not in the form of an argument which you can give to someone, it just suffices to have the right sort of experience without needing any additional reasons. — Fafner

How do you know that?
Well, because you told me so, which makes it a dogmatic claim. You don't get Agrippa's Trilemma, because you keep claiming that it is so, because you say so. That is what makes it dogmatic.

How do you know that? — Mikkel

Know what?

Know what? — Fafner

That you are perceiving them!
How do you know that?

That you are perceiving them!
How do you know that? — Mikkel

What do you mean? You know that you perceive something by perceiving it, how else?

What do you mean? You know that you perceive something by perceiving it, how else? — Fafner

How do you know that it is something and not an illusion?
You take for granted that there is a screen in for of you. How do you know that there is? How do you know, that it is not a simulation or that you are not a Boltzmann Brain? How do you know, that this something is, what you claim, it is? How do you, that it is not something else?
How do you know???

How do you know that is something and not an illusion? — Mikkel

Now you are just using the Cartesian argument which I discussed in my other post. I thought that your 'trilemma argument' was a different argument from the classical argument from illusion (and by the way, you said previously you agreed with me that the argument is incoherent).

Now you are just using the Cartesian argument which I discussed in my other post. I thought that your 'trilemma argument' was a different argument from the classical argument from illusion (and by the way, you said previously you agreed with me that the argument is incoherent). — Fafner

It is incorrect, because I believe despite evidence that you are something even if I wasn't around. Of course, I believe I will die one day.
Now you take for granted that there is something. E.g. I exist :) But you have given no evidence. Further there is a problem with your notion of taking for granted. Let us say, I take for granted that there is a God. Now that is not evidence for a God, so why should the fact, that I take for granted that you exist, be evidence for your existence.
You still haven't given any evidence. It boils down to that I have no evidence, therefore you have evidence. Namely that when between P and non-P, non-P is wrong, then P is true. That is not how logic works.
You have made a naive realistic claim - "You know that you perceive something by perceiving it, how else?", but you have given no evidence.
#I know, that I perceive something by perceiving it.
#I know; that I don't perceive something by perceiving it, because I know, that I am a Boltzmann Brain.
#Either case is not knowledge.
You don't get the last one, do you?

To be an old school Skeptic means in some sense not to believe in knowledge, just like some people don't believe in the concept of a god/gods.
I use the word knowledge as an idea that some people believe in, but I don't believe in knowledge.
You don't seem to understand doubt.
I doubt that I am in the world, you know you are in.
I doubt that I am a Boltzmann Brain and I doubt that we are in a simulation.
But none of that is evidence for the fact that we have knowledge.

You have made a naive realistic claim - "You know that you perceive something by perceiving it, how else?", but you have given no evidence. — Mikkel

The evidence is simply my perceptual state (of seeming to see that something is the case in the world).

Again, you are misunderstanding what 'non-inferential' means. It means that your evidence is simply the state on which you base your belief. And you don't need further evidence (to prove that your original evidence is good, or is not the result of an illusion etc.) precisely because your experiential state has intrinsic justificatory power to support what is believed, which is independent of any further premises (hence it is called 'non-inferential').

How do you explain a hallucination?

I once lived at the coast and could look out on a bay. Once day I saw an island, which I hadn't seen before and never saw again; i.e. a hallucination. How is that possible?
How can an experience be wrong?
Now if you claim that hallucinations are not real, then I have to ask - How do you know that?

Now if you claim that hallucinations are not real, then I have to ask - How do you know that? — Mikkel

They are sometimes real, but not always (at least they need not be, or you can't prove that they have to). I tried to show in that other post on skepticism that hallucinations (for their intelligibility as hallucinations) presuppose that there's also a possibility to perceive things just as they are in reality. Think about it this way: what makes something into a hallucination? The fact that when you have it, it looks to you as if things around you are in a certain way (when in fact they aren't). But this means that there's also the possibility for things to be in the world just the way they appear, which will not be a state of hallucination, since your experience will portray accurately the way things are in reality (so if it is possible for your experience and the world no to match, then it is also possible - at least logically - for them to match).

This is the first step. The second step will be to show that we are justified to rule out or ignore the sorts of hallucinations or illusions of the kind to which the skeptic appeals in his argument. I also discussed this to some extent in the other post, though a bit more needs to be said about that, since people didn't get the idea (I can elaborate on this if you wish).

How can something be not real?
If you have a hallucination, then is that a not real or unreal hallucination or is it real?
What is real and how do you know that?
What is not real and how do you know that?

In other words within methodological naturalism and science a hallucination is a process in a brain, so how can it be unreal? How can something, a brain, produce something unreal?
How can something, which is real, produce something, which is unreal?
Take time, space and processes in the world. Now it is a brain(real) then time and space passes and it becomes unreal. At what time, in what space and what process make something real not real/unreal?

Do you understand that you have made an incoherent argument, because you claim that in one moment some is real and then it turns unreal, but how can something become unreal, which is real? It is no different than ontological dualism, we have two ontological categories; real(matter) and unreal(mind), and something real can turn unreal.
You are taking for granted that something can turn unreal, but that this is real. I.e. unreal is real, because it is really unreal and it is something, which take place in the real; i.e. a brain.

Fafner, you have simply hidden the problem with your claim of real and not. But it doesn't stand up and your claim that all experiences including hallucinations can be explained non-inferential, doesn't hold, because you can't explain the non-real with your model of the world

I didn't mean to say that hallucinations are 'unreal' in your sense, relax...

When you have a hallucination of course your experience is as real as any (and that it is a state of your brain etc). The point is rather that not all experiences are necessarily hallucinations, since the very concept of hallucination presupposes that it's at least also possible to perceive directly how things are in the objective reality (and by "unreal hallucination" I just meant a genuine experience - e.g. seeing a real tree as opposed to just hallucinating a tree etc. - I didn't mean that the experience of hallucinating itself is not real).

Now I see a tree. That is non-inferential, I will accept that for now. But what that have to do with the objective reality? What do you mean by objective reality and how do you know that there is such a thing as an objective reality?

What do you mean by objective reality and how do you know that there is such a thing as an objective reality? — Mikkel

The fact that we're able to do science, and objectivity has a meaning and use.

Now I see a tree. That is non-inferential, I will accept that for now. But what that have to do with the objective reality? What do you mean by objective reality and how do you know that there is such a thing as an objective reality? — Mikkel

"Objective reality" simply means that things are exactly as they appear to you perceptually (when you see a tree, there's really a tree in front of you etc.). Really, there's nothing to explain here.

And about the "how do you know?" part, it's a bit complicated, but I'll try to keep it simple. The basic idea behind the skeptical argument (that is, the argument from illusion) is that even what we take to be the best cases of knowledge aren't really knowledge because we cannot rule out every conceivable possibility of us being wrong. So we have two options according to the skeptic for ways for the world to turn out to be: for every imaginable experience (say of seeing a tree) either a. things in the world match exactly the way they appear to you or b. you are completely deceived about everything in your experience since you are perpetually hallucinating or a brain in a vat etc. And since no piece of perceptual evidence could support favoring possibility (a) over (b), you cannot know that you are living in (a) and not (b) (and hence you can't know anything).

But notice the difference between scenarios (a) and (b). Suppose that scenario (a) is the actual one, what this world would be like? Well, that would be a world in which things are almost exactly correlated with the way they appear to you perceptually, at least in the typical cases (since the skeptic allows us to choose any case we wish as the best candidate for knowledge; and as I've argued before, for every experience of things appearing to you to be such and such, there's a possibility that things in the wold are indeed such and such, even if they are not so in the actuality). And now let's consider world (b). The way the example set up, world (b) is designed in such a way that things look to you exactly as if you are in world (a) (but you aren't), and you have no way to tell (based on your experience). So in this world, reality has absolutely nothing to do with the way things appear to you, but somehow, by virtue of some miracle or extremely clever design, your appearances are correlated with the way the world would've been if world (a) were the actual one (because otherwise it would not be a case of an illusion).

And now, keeping all this in mind, let us assess the relative probabilities of worlds (a) and (b). Given that you are having right now an experience as if you are living in an (a) type world, what are the odds that you really are? I think they are pretty high (or even extremely high - and conversely, they are very low for (b) being the actual world), and this is shown by the mere fact that in order to persuade you that you might be mistaken, the skeptic had to concoct this very bizarre and unlikely sci-fi story about brains in a vat or whatever. But the world as you perceive it, is such (if we assume for a second that it is the actual world) that in it scenarios of the kind that the skeptic envisions are extremely unlikely; that is, cases in which reality matches appearances are way more common than when it doesn't (because by hypothesis, it is a world where whenever you see a tree there's really a tree, since normally no one tries to deceive you etc.). And that means that it is much more likely for your experiences (taken by themselves) to turn out to be right than wrong, since it would not be a coincidence if your appearances corresponded with reality, but it would be an extreme coincidence if (despite their internal coherence etc.) they actually didn't.

So I believe that we should conclude that we have a very good reasons to favor the belief that we actually live in world (a) rather than (b), since given the extreme unlikeliness that all our experiences are systematically deceptive (as the skeptic imagines), we are perfectly entitled to ignore such possibilities and trust our senses at face value. And now if you supplement all this with my previous account of non-inferential justification, you can actually get from all of this an account of a genuine perceptual knowledge of the world.

You don't get that you are doing a case of begging the question- (

Suppose that scenario (a) is the actual one)

-when you assign the odds.
Now I don't do metaphysics and epistemology as knowledge. I do it as different beliefs and the telling sigh is here that so do you:

So I believe...

Now Fafner, the objective reality does not conform to what you believe, not matter what you believe. That you can't understand, that you have just admitted that it is a belief and not knowledge, tells me, that you don't understand the skeptic position - You don't know what reality is and you only believe.
Further you are biased because of theses words:

...by virtue of some miracle...

You turn it being about God, if reality is not as it appears. You don't understand the examples in this thread, do you? None of them has to do with God. Both examples are naturalistic.

So you have shown your hand - You are begging the question if you assume you can determine the odds. You admit that you believe and you argue as if this thread could be about God. I do get that you properly don't believe in God, but neither do I. I believe reality is as it appears, but I don't know that, nor do I know the odds.

In the end no matter what you believe won't determine what reality you are in. No matter how you believe, it won't affect what reality you are in. You don't control reality based on how you think, reality controls you. That is part of what objective reality entails.
You are doing magical thinking, because you believe that your thinking determines, what reality is. It is similar with some religious believers, namely that some people don't like the unknown and will try to offer beliefs as evidence. You have given no evidence, because you are begging the question, when you believe you can assign actual odds. Further it appears that you don't understand that you believe and don't know, despite you use words like belief and trust. You believe and trust in a naturalistoc reality, you just have to give up the notion that you know

You completely misunderstood my post, that's all that I can say.

The simulation argument:

1. The fraction of human-level civilizations that reach a posthuman stage (that is, one capable of running high-fidelity ancestor simulations) is very close to zero, or
2. The fraction of posthuman civilizations that are interested in running ancestor-simulations is very close to zero, or
3. The fraction of all people with our kind of experiences that are living in a simulation is very close to one — Michael

If there are more Sims than there are non-Sims then we're more likely to be Sims. — Michael

This whole set of logic presupposes that what we are is the instantiation, or execution, of whatever physics makes us up. But a simulation of thing X is not an instance of X. X already exists (is defined, and the definition is enough), and the simulation simply imparts some truth about X to whatever is executing the simulation.
So the list above leaves off the 4th possibility: that what we are is not the execution of the steps. Is 3+3 not equal to 6 until something performs that arithmetic? There are arguments for both sides of that debate, so I will not present it as truth, just a 4th option.

I think the simulation argument is less about us and more about the world we live in.

I think the simulation argument is less about us and more about the world we live in. — Alec

Granted. I must reword then.

This whole set of logic presupposes that what things are is the instantiation, or execution, of whatever physics makes defines. But a simulation of thing X is not an instance of X. X already exists (is defined, and the definition is enough), and the simulation simply imparts some truth about X to whatever is executing the simulation.

That said, there is another presupposition that IS about us and not just things: That what we are is just a physical thing/process and not in need of some immaterial experiencer of the thing X, simulated or otherwise. I agree with that assumption, but it is still an assumption. This sort of groups under item 1: An ancestor simulation is not possible because a simulation of an ancestor is not a full simulation of that ancestor unless there is a way to grant the immaterial experiencer to the simulation. Something like that.

Possibility 5 then: The real world (the one running the simulation) is not a human civilization at all, but a much higher tech thing which can execute simulations of trivial things like a human civilization at will. The simulation need not be a simulation of its native underlying reality. I don't think that scenario is covered in any of your options.
My possibility 4 stands in such a scenario: Such a simulation is not the creation of this reality, but merely an analysis tool to learn about the already-defined reality.

You completely misunderstood my post, that's all that I can say. — Fafner

Here what I can do:
Suppose that we start with the assumption that there is no knowledge out there in the objective reality.
Then I construct evidence:
Knowledge is a cognitive construct, an idea just like the idea about God. Some people treat God as real, some people treat knowledge as real.
Knowledge is not real like a tree, you can't see, touch, hear, smell and so on knowledge. The idea that there is an objective reality independently of the mind, which you none the less, have access to is a contradiction, because reality can't be independent of you and yet you have access to it.
Reality is your experiences and your beliefs about how to make sense of it. There is no "The objective reality", because then subjectivity is not a part of reality.
That facts, evidence, truth, knowledge and so on matter to you is because, that it matters to you, is what makes it subjective.

The idea that there is an objective reality independently of the mind, which you none the less, have access to is a contradiction, because reality can't be independent of you and yet you have access to it. — Mikkel

Why not? That's a really extravagant claim to make for someone who calls himself a "skeptic".

Reality is your experiences and your beliefs about how to make sense of it. There is no "The objective reality", because then subjectivity is not a part of reality. — Mikkel

This simply begs the question. If this is meant as an argument to prove what you said in the first quote ("mind independent reality is a contradiction"), then you cannot start from a premise which equates reality with your experiences. You indeed experience reality through you subjective states, but it doesn't follow that reality is identical with them.

That facts, evidence, truth, knowledge and so on matter to you is because, that it matters to you, is what makes it subjective. — Mikkel

What you say here doesn't follow. If dogs matter to me subjectively, that doesn't prove that dogs themselves are 'subjective'.

The problem is, once we start applying your reasoning to things in general, then it seems to amount to us saying that the experiences that we have of an external world cannot be replicated by a simulation or otherwise. That'd be extraordinary indeed, if we can somehow prove definitively that we cannot be brains in vats or living in a vivid dream world. Unfortunately, I think it's more likely that that isn't the case, hence the persistence of skepticism.

I use the word knowledge as an idea that some people believe in, but I don't believe in knowledge.
You don't seem to understand doubt. — Mikkel

I don't believe that you don't believe you know anything. Do you know how to find your way home? Do you know the difference between a tree and a pork sausage? Do you know how to swim or ride a bike?

It's true that we don't know what are the metaphysical conditions that give rise to our experience of a world of familiar, more or less invariant objects, landscapes, day and night sky, animals and people. About that we may only speculate. And we have good reasons to think some speculations are more plausible than others, even if we cannot prove that they are.

On the other hand we may indeed have knowledge about those metaphysical conditions, but we can never achieve discursive certainty. In other words we may know, but we cannot know that we know, because that would involve (per impossible) the absurd discursive regress of the ancient skeptics; the so-called 'criterion' problem.

The kind of doubt you are valorizing seems trivial and empty.

The problem is, once we start applying your reasoning to things in general, then it seems to amount to us saying that the experiences that we have of an external world cannot be replicated by a simulation or otherwise. That'd be extraordinary indeed, if we can somehow prove definitively that we cannot be brains in vats or living in a vivid dream world. Unfortunately, I think it's more likely that that isn't the case, hence the persistence of skepticism. — Alec

My reasoning assumes no BIV, a separate thing that experiences a sensory stream that is not the same sort of thing that is the experiencer. It assumes (and does not assert) that consciousness is just a physical process, no more. If this is not true, then all rules are off concerning whether a simulation of anything can exist at all.

So given my assumption, it is easily proven that a perfect simulation of some actual state of the universe (say a chosen person) is impossible. But an imperfect one is not, say simulated as a neural-chemical body with a finite world to inhabit. This simulation, being finite and imperfect, would have a different history than the real person who is being modeled, but the simulated person would be conscious (again, given the assumption of consciousness is a physical process, and for the most part, not a quantum process). If the simulation took a scan of my body as part of the initial state, then the simulated person would not know it was not me, but might quickly figure it out if the finite nature of the world is at all obvious.

Now the main part of my point: The simulation need not run at all for the simulated person to be conscious. All that is needed is the initial definition of state and the definition of how the simulation is to proceed from that state. This is what I meant by the fact that 3+3 is equal to 6 even if the arithmetic is not actually performed by some mechanism.

Never said you assumed BIVs. I merely used the case of BIVs to demonstrate what I think is a wild assumption with your approach. As far as I see it, the only way for your argument to undermine the simulation argument to work is for you to somehow point out some feature or element about the nature of our understanding of the world (or our experience of it) that cannot in principle be replicated by a computer program. If it can be, then we cannot ascertain whether or not we are looking at a simulation when talking about the world we live in.

Of course, this sort of discovery seems as likely as the discovery that there is a feature of our experience that is impossible to replicate, whether by a BIV, or demon, or a vivid dream scenario. Now you may not be alone in thinking this. I believe this is the sort of suggestion made in the "Answering the Skeptic" thread, but as for my own take on it I find it to be a bit too extraordinary for my own liking.

Your example deals with a conscious person, but again, I must point out that the simulation argument (as well as the BIV argument) is more about the world we find ourselves in rather than who we are.